Figure 4.

Gene order structures of hypervariable segments. SAG contigs with homologs to genes located in the hypervariable region HVR2 in the marine SAR11 genomes, as identified by BLAST search (E < e-10). The intensity of the red color indicates the number of SAR11 genomes for which a homolog was identified in HVR2 (pink = 1; dark red = 5). Blue color indicates glycosyltransferases identified as gained in LD12. Cluster annotations are shown, with cluster numbers used for clusters with no annotated gene name.